In the last few years the fields of evolution and molecular developmental genetics have intersected to produce new results and insights which have generated much current excitement. It is now clear that the very few primary model organisms that are currently utilized in biomedical research are not sufficient to let us understand the tremendous diversity of animal and plant life on earth. Understanding the generation of this diversity, honed over eons of evolution, will most likely provide important insights into the mechanisms that cause organ variation and the evolution of species. The goal of the proposed Cold Spring Harbor Conference on Evolution of Developmental Diversity to be held April 17 to April 21, 2002, 2004, and 2006 is to bring together a broad range of scientists studying various molecular and genetic aspects of animal and plant biology with a strong emphasis on morphological and functional comparisons of organismal diversity and evolution. This conference is expected to attract approximately 250 scientists from around the world. This biannual meeting will provide a format for the exchange of ideas and information among both junior and senior scientists for the discussion of the latest research findings and technical advances towards the study of the evolution of developmental mechanisms that diversify animals and plants, and fosters scientific collaboration. Eight topics (eight sessions) have been selected for detailed discussion as a reflection of the most advanced and interesting areas of study in the evolution and development field (Evolution of Gene Regulation, Genetics I and II, Genomics, Axial Pattern, Segmentation and Regionalization, Organogenesis: Morphological Innovation, Speciation). Three established scientists per session are invited to present a relatively global perspective of their work (one of which will also act as the chairperson for that session), while the remainder of the talks will be selected from the submitted abstracts. Other participants are able to present their research in poster sessions to be held during the conference. This format allows the participation of many junior scientists, giving them a format to present their latest work.